Spot sander for swimming pools



Mam}! 1965 D. D. PRICE ETAL 75, 34

SPOT SANDER FOR SWIMMING POOLS Filed Feb. 25, 1965 INVENTORS LEN/[Z 0 PR/CZ BY [OW/N PAES'EV United States Patent 3,175,334 SPGT SANDER FOR SWEMMING P0013 Daniel D. Price, El Monte, and Edwin E. Presby, West Covina, Calif., assignors to Rainbow Plastic, El Monte, Calif., a partnership Filed Feb. 25, N63, Ser. No. 260,573 4 Claims. or. 51-393) This invention relates to abrading and to rigid tools therefor. More particularly, the invention relates to a spot sanding accessory for swimming pool maintenance units.

Swimming pools often are spotted when objects are dropped into the pool and are corroded or decomposed by action of the water thereon. The rate at which localized stains are produced is accelerated Where chemical additives, such as chlorine, are present in the water for hygenic purposes. In the past it has been necessary to dive into the pool to remove the staining object and to abrade the surface of the pool to remove the spot. It is not always convenient to dive into the pool to remove a bobby-pin or leaf, and it not sensible to drain the pool to remove such an object.

The present invention provides inexpensive and effec tive apparatus for removing ferromagnetic objects dropped into a swimming pool and for abrading the exposed surface of the pool liner to remoVe a stain produced locally in the pool by corrosion of an object dropped into the pool. Use of the present invention does not require that the pool be drained.

Generally speaking, the present invention provides a swimming pool spot sander accessory comprising a base member and an abrasive element. Means are Provided for securing the abrasive element over a selected portion of the base member. Means are also provided on the base member opposite from the selected portion thereof for releasably engaging a cooperating end of an elongated pole or the like. A preferred form of the invention includes a magnet for picking up ferromagnetic articles from the bottom of the pool.

The above mentioned and other features of the present invention are more fully set forth in the following detailed description and explanation of the invention, taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an exploded perspective assembly view of a spot-sander according to the present invention; and

FIG. 2 is a cross-sectional elevation view of the apparatus shown in FIG. 1.

' Referring to the drawings, a sander accessory it according to the present invention is comprised of a base member, a clamp member 12, and an abrasive element 13. The base member preferably i rectangular in plan view and defines a lower surface 14 which, as illustrated in FIG. 2, is substantially cylindrical and extends across the entire lateral extent of the base member. The lower surface is convex downwardly and extends to parallel side edges 15 spaced apart transversely of the base member. The base member also has a concave upwardly inner orupper surface 16 disposed substantially concentric to the lower surface. A pair of spaced apart, parallel bulbed lips 17 are defined between the upper and lower surfaces and are curved smoothly between the upper and lower surfaces. A pair of spaced apart parallel webs 18 are formed across the ends of the base member between lips 17 and impart rigidity to the 'base member so that the lips are spaced apart a predetermined distance. Preferably, the webs are disposed at right angles to the cylindrical inner and lower surfaces of the base member.

A flat portion 19 is defined in the lower surface of the base member substantially midway between edges 15. A recess 20 is formed in the base member to open into flat portion l9. A galvanized ferrous washer 21 is secured across the upper lateral extent of the recess preferably by molding the washer into the base member during the fabrication of thebase member according to the process described below. A rubber magnet 22, having its lower surface flush with the lower surface of the base member adjacent recess id, is engaged in the recess and is maintained therein by magnetic attraction to the ferrous washer. If desired, a bonding agent may be applied to the interface between the magnet and the washer. The rubber magnet is provided by embedding finely divided iron filings in a body of rubber and then permanently magnetizing the metal impregnated rubber to provide a permanent magnet which is magnetically effective through sandpaper abrasive element 13 disposed over the magnet. The rubber magnet is resistant to corrosion by salt or chlorinated water.

A socket portion 2a is connected to the base member opposite from the concave downwardly lower surface. Preferably, the socket portion is molded integrally with the base member and is in the form of a circularly cylindrical sleeve extending upwardly from upper surface 16 concentric to recess 29. A preferably circularly cylindrical recess 25 is defined within the sleeve and is adapted to receive the lower end of a tubular support 26 engaged therein, but it is within the scope of the present invention that the socket member belocated ottcenter of the sander and that recess 25 not be circularly cylindrical. The support preferably is in the form of an elongated pole, shown in FIG. 2 as tubular, and which is primarily frictionally engaged within the socket portion. The exterior surfaces of the socket portion are spaced apart from the opposing inner vertical surfaces of bulbed lips 1'7.

An abrasive element 13 is engaged with the lower surface of the base member and extends over the lips into engagement with the inner surface of the base member. In a preferred embodiment of the present invention the abrasive element is a length of waterproof sandpaper having a width corresponding to the distance between the outwardly facing surfaces of Webs l3 and having a length suflicient to wrap around both lips 1'7 into engagement with surface 16 (see FIG. 2). As noted above, magnet 22 is of sufficient strength to be magnetically effective through the strip of sandpaper.

The present invention provides clamping means for securing the abrasive element to the base member. In a preferred form of the invention, clamping means are provided in the form of clamping member 12 which has a rectangular and planar body configuration having spaced apart end edges 23. The lateral spacing between the edges of the clamp member exceeds the spacing between the opposing vertical surfaces of bulbed lips 17. A circular aperture 29 is formed through the central portion of the clamp member and has a diameter greater than the outer diameter of the socket portion to allow the socket portion to pass through the aperture when the clamp member is engaged to secure the abrasive element to the base member. A pair of downwardly depending, parallel and spaced apart flanges 3d extend from the bottom of the clamp member. The flanges are laterally resilient and are adapted to engage. the turned-over portions of the sandpaper strip disposed along the inner sides of bulbed lips 17. Accordingly, the difference between the distance of the outwardly exposed surfaces of flanges 3G and the opposing surfaces of lips 17 is less than twice the thickness of a strip of sandpaper engaged with the base element and wrapped over the lips. The sandpaper element is secured to the base member by inserting the socket portion of the base member through aperture 29 of the clamp member and deflecting flanges 30 toward the socket portion by engagement with the or a) base member. The opposite ends of the sandpaper element are thus compressively engaged between flanges 3t) and immovable lips 17. The movement of the flanges axially of socket portion 24 serves to tension thesandpaper strip across surface 14 of the base member.

In a preferred embodiment of the presen invention, the base member and the socket portion are molded in one piece from a thermoplastic material such as acrylonitrile-butadiene-styrene resin, such as Cycolac resin, marketed by Marbon Chemical Co. The clamp member and flanges 3b similarly are molded in one piece from similar material in a preferred form of the invention. Such material provides the lateral resiliency of flanges 3t suflicient to ensure proper clamping action of the sandpaper between the flanges and lips 17 of the base memb r. ABS resins, such as the resin marketed under the trade name Cycolac, are preferred in the fabrication of the present invention since such resins exhibit excelent resistance to materials added to the water of swimming pools and have excellent veathering characteristics. Nylon may also be used to advantage in the present invention.

FIG. 2 shows support member in secured in recess 25 by a spring retainer 4d fabricated in one piece from polymerized formaldehyde acetal resin and more fully described in application Serial Number 269,572, filed February 25, 1963, by the inventors of the present invention. The retainer has diverging spring leaf arms 41 each having laterally an extending lug 42 passed through one of a pair of apertures 43 through the support pole at diametrically opposed locations adjacent the end of the support pole. A recess 44 for receiving each lug is provided in the wall of recess 25 of the sander socket portion. Recesses 44 may be disposed locally of the socket portion, or they may be combined in a single recess circumferentially of the interior of socket portion In operation of the present invention, a length of waterproof sandpaper is secured to the convex lower surface of the base member and is secured thereto by the clamp member. The assembled parts of the accessory are then secured to one end of the elongated pole and the accessory is inserted into the swimming pool through the waer therein. If the foreign object in the pool, causing the stain which is desired to be removed, is a ferrous object the object can be removed by picking it up through use of the magnet. After the foreign has been removed, the spot is abraded to remove the stain.

While the invention has been described above in conjunction with specific apparatus and specific compositions of material, this has been by way of example only. Other compositions and geometries of the various components of the apparatus may be relied upon without departing of the scope of the present invention.

What is claimed is:

1. A sanding accessory comprising a base member, the base member defining a lower surface having spaced apart side edges, a lip formed in the base member along the extent of each of said edges, the lips defining a pair of spaced apart opposed surfaces, the base member defining means for engaging the accessory with support means for the accessory, a flexible abrasive sheet engaged with the base member lower surface and extending over the lips to overlie the opposed surfaces of the lips, and means for tensioning and securing the abrasive sheet to the base member comprising a clamp member defining a pair of flanges which are normally spaced apart a distance less than the distance between the opposing lip surfaces by an amount less than double the thickness of the abrasive sheet, the clamp member being movable toward the side of the base member opposite from the lower surface thereof with the flanges disposed adjacent the lips so that the flanges engage the abrasive sheet adjacent the opposed lip surfaces and are deformed laterally toward each other, continued movement of the clamp member toward the base member tensioning the abrasive sheet on the base member by pulling the opposite ends of the sheet over the lips and thereafter compressibly maintaining the ends of the sheet en aged vith the opposing surfaces of the lips.

2. A sanding accessory comprising a rectangular base member having a substantially semicircular cylindrical lower surface convex downwardly of the base member, a lip in the base member along the elongate extent of each linear edge of the lower surface, the lips defining a pair of spaced apart opposed surfaces, a socket formed in the base member and adapted to receive pole means for supporting the accessory, a flexible elongated abrasive sheet engaged with the base element circumferentially of the lower surface, the abrasive sheet having an extent between opposite ends thereof in a direction circumferentially of the lower surface greater than the extent of the lower surface in the same direction, the ends of the abrasive sheet extending around the adjacent lips to overlie the opposed surfaces thereof, and a clamp member defining a pair of projections normally spaced apart a distance less than the distance between the lip surfaces by an amount less than double the thickness of the abrasive sheet, the clamp member being movable toward the base member over the socket so that the projections engage the ends of the sheet and deform toward one another to clamp the ends of the sheet between the projections and the lip surfaces, movement of the clamp member toward the base member drawing the ends of the sheet over the lips to tension the sheet across the lower surface of the base member.

3. A sandin accessory according to claim 2 including a recess in the base member lower surface, and a perinament magnet disposed in the recess magnetically effective through the abrasive sheet.

4. A spot sander for swimming pools comprising a rectangular base member, the base member defining a substantially cylindrical first surface convex exteriorly of the base member, the base member defining a substantially cylindrical second surface substantially concentric to the first surface and concave exteriorly of the base member, the base member defining a pair of lips between adjacent linear edges of the first and second surfaces, the lips defining a pair of opposed spaced apart surfaces, the base member further defining a cylindrical socket portion raised from the second surface and adapted to receive an end of a pole member, a flexible abrasive ele ment engaged across the first surface and extending over the lips to spaced apart ends overlying the lip surfaces, and a clamp member having an aperture therethrough for passage of the socket portion thercthrough, the clamp member having a pair of laterally resilient parallel flanges extended therefrom at locations diametrically opposed across the aperture, the flanges having opposite extremities diametrically of the aperture which are spaced apart a distance less than the distance of the opposed lip surfaces by an amount less than double the thicknes of the abrasive element, the clamp member being engagable with the base member concentric to the socket portion with the flanges compressibly engaging the ends of the abrasive element between the flanges of the lips, movement of the clamp member toward the base member after engagement of the flanges with the abrasive element tensioning the abrasii e element across the base member by drawing the ends of the element over the lips.

References Cited by the Examiner UNITED STATES PATENTS 1,501,192 7/24 Severus 5l386 2,056,182 10/36 Gardner 5l-1l0 2,138,288 11/38 Bailey 15-231 2,790,193 4/57 Wilding 15-23l 2,827,651 3/58 Rezk 15-210 2,934,779 5/60 Wollner 1523l X FOREIGN PATENTS 888,3 .4 1/62 Great Britain. LESTER M. SWINGLE, Primary Examiner.

Patent Nob 3,175,354 1965 Daniel D6 Price et al a It is hereby certified that error a ent reqiiring corre t c ion and that corrected, belo ppear's in the above numbered patw.

the said Letters Patent should read as Column 2,

line 26, for "belocated" read H be located 'column 5, line 45, a ter "foreign" insert we article column 4, line 58, for "of" irst occurrence read and Signed and sealed this 24th day of August 1965 (SEAL) Attest:

ERNEST w. SWIDER EDWARD J. BRENNER Attcsting Officer Commissioner of Patents 

1. A SANDING ACCESSORY COMPRISING A BASE MEMBER, THE BASE MEMBER DEFINING A LOWER SURFACE HAVING SPACED APART SIDE EDGES, A LIP FORMED IN THE BASE MEMBER ALONG THE EXTENT OF EACH OF SAID EDGES, THE LIPS DEFINING A PAIR OF SPACED APART OPPOSED SURFACES, THE BASE MEMBER DEFINING MEANS FOR ENGAGING THE ACCESSORY WITH SUPPORT MEANS FOR THE ACCESSORY, A FLEXIBLE ABRASIVE SHEET ENGAGED WITH THE BASE MEMBER LOWER SURFACE AND EXTENDING OVER THE LIPS TO OVERLIE THE OPPOSED SURFACES OF THE LIPS, AND MEANS FOR TENSIONING AND SECURING THE ABRASIVE SHEET TO THE BASE MEMBER COMPRISING A CLAMP MEMBER DEFINING A PAIR OF FLANGES WHICH ARE NORMALLY SPACED APART A DISTANCE LESS THAN THE DISTANCE BETWEEN THE OPPOSING LIP SURFACES BY AN AMOUNT LESS THAN DOUBLE THE THICKNESS OF THE ABRASIVE SHEET, THE CLAMP MEMBER BEING MOVABLE TOWARD THE SIDE OF THE BASE MEMBER OPPOSITE FROM THE LOWER SURFACE THEREOF WITH THE FLANGES DISPOSED ADJACENT THE LIPS SO THAT THE 